Research shows your body’s microbiome has nearly 39 trillion bacteria.1 During early years, your family, dietary intake and environmental exposure contribute to the variety in your microbiome, influencing your lifelong health. Everyday activities such as brushing your teeth, eating, kissing someone or handling a family pet also affect your microbiome.

This composition may be as distinct to you as a fingerprint and plays an enormous role in disease prevention, and influences the function of your skin, lungs, breast and liver.2 Harmful bacteria can trigger illness and disease, which is frequently treated with antibiotics. Of the 10 most commonly prescribed, three are from the antibiotic class of fluoroquinolones.3

The Food and Drug Administration (FDA) first added a boxed warning to fluoroquinolones in 2008, due to the increased risk for tendinitis and tendon rupture.4 Boxed warnings, also referred to as black box warnings, appear on prescription drug labels designed to call attention to serious or life-threatening risks.5

An additional warning was added in 2011 for those suffering from myasthenia gravis, and updates were included in 2013 describing irreversible peripheral neuropathy.6 Most recently, the FDA warned fluoroquinolone antibiotics may increase the occurrence of ruptures or tears in the aorta.7

Latest FDA Warning Links Fluoroquinolones With Aortic Damage

The aorta is the main artery in your body supplying oxygenated blood to your circulatory system. The artery comes from the left side of your heart and runs down the front of your backbone. The review by the FDA found fluoroquinolone antibiotics increase the risk of tears in the aorta, also called aortic dissections, or ruptures of an aortic aneurysm, leading to excessive bleeding and death.

The findings occurred when antibiotics were given by mouth or through an injection. This led the FDA to caution against the use of fluoroquinolone antibiotics in those at risk, unless there are no other treatment options available.

Specifically, the antibiotic should not be used in those who are at risk for, or have a current, aortic aneurysm, such as those suffering peripheral atherosclerotic vascular disease, hypertension and specific genetic conditions such as Ehlers-Danlos syndrome or Marfan syndrome.8

Findings were pulled from four published observational studies, which taken together demonstrated a consistent association between aortic dissection or rupture and fluoroquinolone use. The underlying mechanism could not be determined from those studies.

Some of the commonly used fluoroquinolones include ciprofloxacin (Cipro), levofloxacin (Levaquin), gemifloxacin (Factive) and moxifloxacin (Avelox). These are widely prescribed to treat upper respiratory and urinary tract infections. In a statement, the FDA warns:9

“Fluoroquinolones should not be used in patients at increased risk unless there are no other treatment options available.